Many forms of linear motion devices are known in the art. Examples of these devices are manufactured by Star GMBH of Sehweinfort in Germany which include a ball screw drive mounted in conjunction with a set of external guide rods which are provided with a frame, the guide rods guiding a carriage driven by the ball screw drive to a required position. Structures of this type are exemplified by the contents of FIG. 2. They are however heavy by nature because of the external mounting of the guide rails, exemplified by FIG. 2, thereby requiring that these guide rails be load bearing and thus relatively large in diameter.
Another type of structure similar in operation to FIG. 2 is Manufactured by INA and includes a member as illustrated in FIG. 4 which includes guide rafts mounted externally on a section upon which a carriage will move. The guide rails are inserted in channels during manufacture and retained in position by passing the section shown in FIG. 4 past a stationary tool and rolling the flanges of the channels to retain the guide rails in position as described in FIG. 5.
The THK Co., LTD. of Tokyo Japan provides an LM Guide (a registered Trademark) to be incorporated in a linear motion device as described at pages 12 through 21 of their Catalog No. 26E. A guide rail of this generic type is incorporated in a device manufactured by Star GMBH in their catalogue for linear motion devices which describes an open top "U" shaped section having a guide rail of the form of the LM Guide therein, bolted in place within a machined channel at the bottom of the "U" shaped section. There is an inherent problem in the setup of such a guide as described at page 16 to 20 of the THK catalogue which requires extensive alignment procedures during the manufacture and setup of the unit. The use of this ball rail in linear motion devices is very expensive and results in complex installation procedures as described on pages 16 to 20 of the THK catalogue discussed above. For example the cost may be about $2000 per four meters of guide rail used in the device. A simpler, less time consuming, more cost effective solution is therefore very desirable.
Zakron Industries of Pickering, Ontario, Canada manufactures a CNC linear motion system for a shear which is constructed from an extruded section of aluminum. This aluminum section includes a substantially hollow hat section shape which is continuous in cross section, as illustrated in FIG. 8, which has a slot machined therein at the top thereof to allow gauging of a workpiece on a shear device such as Compu-Shear, a tradename of Zakron Industries. The section also includes channels for guide rails internally within the section as seen in FIG. 8. The guide rails are installed in the channels as shown in FIG. 8 by using any known technique so that the flanges on each side of the channel retain the guide rails in a similar manner as to that illustrated in FIG. 4 and 5. In use a carriage therefore runs internally within the section driven by a known ball screw drive such as those manufactured by THK. The Compu-Shear devices therefore offers the added reliability and safety of an enclosed system with out the need for bellows type covers or the like. However in spite of its many advantages over other known linear motion devices it is not always suitable for installations where space is at a premium, nor is it designed to resist any torque on the unit as a result of any material handling efforts of those using the unit, for example bumping by a material handling truck in a direction at fight angles to the direction of motion of the linear motion device.
Zakron Industries of Pickering, Ontario, Canada manufactures a CNC linear gauging system for a brake, which is constructed substantially as shown in FIG. 2, which may be provided integral with a new machine when manufactured, or which may be installed on an old brake thus bringing computerized numerical control gauging to older machines without the costly expense of purchasing a new brake. A new control for motion of the brake itself may or may not be provided. However the gauging system is heavy and requires extensive setup and alignment to ensure proper operation in the field. Therefore there exists a need for a more compact unit which reduces the amount of setup and alignment time required in manufacturing and installation is yet still compatible with the industry standard mounting distances of 200 mm, 400 mm, and 600 mm etc.
Nowhere within the prior art is there provided a compact closed section to be used with a gauging device, the external and internal walls of the compact closed section having formed therewith during manufacture the necessary details to provide strengthening of the section for torque resistance, recesses for the guide rails and corresponding recesses for a load carrying carriage, and allowance for the standard mounting distances for the units to which the gauging device will be mounted.
It is therefore a primary object of this invention to provide a gauging system which is economical to manufacture and operate while still offering the desired precision.
It is a further object of the invention to provide a gauging system which is safer to use and more reliable.
It is yet a further object of the invention to provide a gauging system which is significantly lighter in weight over the prior art structures.
It is yet still a further object of the invention to provide a gauging system which is easier to manufacture.
Further and other objects of this invention will become apparent to a man skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.